One type of prior nonvolatile memory is the flash erasable and electrically programmable read-only memory ("flash EPROM"). The flash EPROM can be programmed by a user. Once programmed, the entire contents of the flash EPROM can be erased by electrical erasure. The flash EPROM may then be reprogrammed with new data.
Prior art personal computer systems typically employ removable data storage media. One common prior art removable storage medium is a floppy disk. A relatively new prior art storage medium is an integrated circuit-based memory card ("IC memory card").
Prior art flash EPROMs are nonvolatile and reprogrammable, and this has permitted the flash EPROM technology to be used for removable data storage. One such prior art application is the flash EPROM memory card ("flash memory card"). The flash memory card typically includes a number of flash EPROMs. The flash memory card can be erased and programmed electrically.
One category of prior art personal computer systems typically include desk-top computers and another category of prior art personal computer systems typically include laptop computers. Many prior art desk-top computers typically employ a 5 volt power supply and many prior art laptop computers typically employ a 3 volt power supply.
Like the prior art personal computer systems, one type of prior flash memory card is typically designed to be used in the 3 volt power supply environment ("3 volt flash memory card"). Another type of prior flash memory card is typically designed to be used in the 5 volt power supply environment ("5 volt flash memory card"). The 3 volt flash memory card is typically used in the 3 volt power supply prior art personal computers and the 5 volt flash memory card is typically used in the 5 volt power supply prior art personal computers.
One disadvantage associated with such prior flash memory cards is that a 5 volt flash memory card is typically unsuitable for use in a 3 volt power supply personal computer and a 3 volt flash memory card is typically unsuitable for use in a 5 volt power supply personal computer. Mismatching the power supply of a flash memory card with that of a personal computer typically causes damages to data store in the flash memory card and the flash memory card itself. Therefore, before inserting a flash memory card into a personal computer, the user typically needs to know the power supply of the personal computer and to the power supply for the flash memory card. This typically causes inconvenience to the user. When the user does not know or loses track of the power supply of a particular flash memory card, the user typically cannot use that flash memory card.
Another disadvantage associated with the prior flash memory cards is that the prior flash memory cards typically cannot be automatically self-configured to different power supply voltages. Typically, when the power supply of a 5 volt flash memory card accidentally drops from 5 volts to 3 volts, the 5 volt flash memory card typically cannot function properly and the data stored in that flash memory card may be damaged. Likewise, when the power supply of a 3 volt flash memory card accidentally rises from 3 volts to 5 volts, the 3 volt flash memory card typically cannot function properly and the data stored as well as circuitry of the memory card may also be damaged.